Homebrew PCBs

You'll find this article at hackaday relevant.
http://www.hackaday.com/2006/10/08/inker-the-hand-inkjet/

dandumit wrote:
>
> Hi Volkan,
> Could you please share info about head driving signals ? What head -
> from what printer ? How's data transmited? SPI ? what tension should
> be applied to fire the head ? how did you found out those info ? I
> have seen an similar article but at that time the nozzles where
> addressed individually.
>
> Regards,
> DAniel
>
> > Hi Dave,
> > I think we need to use fpga because of timing issues. If we assume
> that scanning 1 line (8" width paper/pcb) requires 1 sec and we're
> trying to print at 720dpi, this means that we have 1/(8*720) sec or
> 174 microseconds for each dot. During this time you also need to
> download next position data to the head. The alternative solution can
> be not to print at 720dpi and do multiple pass to achieve 720dpi.
> > Another issue the timing needs to be precise otherwise it can cause
> inconsistency in dot positions.
> > The inkjet head that I'm using requires 212bits for each color (90
> nozzles/color) and uses double edge clocking for the sampling.
> From that your clock frequency should be at least 700kHz.
> >
> > Because of above reasons I have decided to use fpga.
> >
> > Cheers,
> > Volkan
>
>